From: Tim Bird <tim.bird@sonymobile.com>
To: Shuah Khan <shuahkh@osg.samsung.com>, linux-api@vger.kernel.org
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-embedded@vger.kernel.org" <linux-embedded@vger.kernel.org>
Subject: [PATCH] selftest: size: Add size test for Linux kernel
Date: Wed, 19 Nov 2014 13:14:53 -0800 [thread overview]
Message-ID: <546D084D.20002@sonymobile.com> (raw)
This test shows the amount of memory used by the system.
Note that this is dependent on the user-space that is loaded
when this program runs. Optimally, this program would be
run as the init program itself.
The program is optimized for size itself, to avoid conflating
its own execution with that of the system software.
The code is compiled statically, with no stdlibs. On my x86_64 system,
this results in a statically linked binary of less than 5K.
Signed-off-by: Tim Bird <tim.bird@sonymobile.com>
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/size/Makefile | 21 +++++++
tools/testing/selftests/size/get_size.c | 105 ++++++++++++++++++++++++++++++++
3 files changed, 127 insertions(+)
create mode 100644 tools/testing/selftests/size/Makefile
create mode 100644 tools/testing/selftests/size/get_size.c
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 45f145c..fa91aef 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -15,6 +15,7 @@ TARGETS += user
TARGETS += sysctl
TARGETS += firmware
TARGETS += ftrace
+TARGETS += size
TARGETS_HOTPLUG = cpu-hotplug
TARGETS_HOTPLUG += memory-hotplug
diff --git a/tools/testing/selftests/size/Makefile b/tools/testing/selftests/size/Makefile
new file mode 100644
index 0000000..51e5fbd
--- /dev/null
+++ b/tools/testing/selftests/size/Makefile
@@ -0,0 +1,21 @@
+#ifndef CC
+ CC = $(CROSS_COMPILE)gcc
+#endif
+
+#ifndef STRIP
+ STRIP = $(CROSS_COMPILE)strip
+#endif
+
+all: get_size
+
+get_size: get_size.c
+ $(CC) --static -ffreestanding -nostartfiles \
+ -Wl,--entry=main get_size.c -o get_size \
+ `cc -print-libgcc-file-name`
+ $(STRIP) -s get_size
+
+run_tests: all
+ ./get_size
+
+clean:
+ $(RM) get_size
diff --git a/tools/testing/selftests/size/get_size.c b/tools/testing/selftests/size/get_size.c
new file mode 100644
index 0000000..f8ffc80
--- /dev/null
+++ b/tools/testing/selftests/size/get_size.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2014 Sony
+ *
+ * Licensed under the terms of the GNU GPL License version 2
+ *
+ * Selftest for runtime system size
+ *
+ * Prints the amount of RAM that the currently running system is using.
+ *
+ * This program tries to be as small as possible itself, to
+ * avoid perturbing the system memory utilization with its
+ * own execution. It also attempts to have as few dependencies
+ * on kernel features as possible.
+ *
+ * It should be statically linked, with startup libs avoided.
+ * It uses no library calls, and only the following 3 syscalls:
+ * sysinfo(), write(), and _exit()
+ *
+ * For output, it avoids printf (which in some C libraries
+ * has large external dependencies) by implementing its own
+ * strlen(), number output and print() routines.
+ */
+
+#include <sys/sysinfo.h>
+#include <unistd.h>
+
+#define STDOUT_FILENO 1
+
+my_strlen(const char *s)
+{
+ int len = 0;
+
+ while (*s++)
+ len++;
+ return len;
+}
+
+/*
+ * num_to_str - put digits from num into *s, left to right
+ * do this by dividing the number by powers of 10
+ * the tricky part is to omit leading zeros
+ * don't print zeros until we've started printing any numbers at all
+ */
+static void num_to_str(unsigned long num, char *s)
+{
+ unsigned long long temp, div;
+ int started;
+
+ temp = num;
+ div = 1000000000000000000LL;
+ started = 0;
+ while (div) {
+ if (temp/div || started) {
+ *s++ = (unsigned char)(temp/div + '0');
+ started = 1;
+ }
+ temp -= (temp/div)*div;
+ div /= 10;
+ }
+ *s = 0;
+}
+
+print_num(unsigned long num)
+{
+ char num_buf[30];
+
+ num_to_str(num, num_buf);
+ write(STDOUT_FILENO, num_buf, my_strlen(num_buf));
+}
+
+print(char *s)
+{
+ write(STDOUT_FILENO, s, my_strlen(s));
+}
+
+void main(int argc, char **argv)
+{
+ int ccode;
+ unsigned long used;
+ struct sysinfo info;
+ unsigned long long temp;
+
+ print("Testing system size.\n");
+ print("1..1\n");
+
+ ccode = sysinfo(&info);
+ if (ccode < 0) {
+ print("not ok 1 get size runtime size\n");
+ print("# could not get sysinfo\n");
+ _exit(ccode);
+ }
+
+ /* ignore cache complexities for now */
+ temp = info.totalram - info.freeram - info.bufferram;
+ temp = temp * info.mem_unit;
+ temp = temp / 1024;
+
+ used = temp;
+
+ print("ok 1 get runtime size # size = ");
+ print_num(used);
+ print(" K\n");
+
+ _exit(0);
+}
--
1.8.2.2
next reply other threads:[~2014-11-19 21:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-19 21:14 Tim Bird [this message]
[not found] ` <546D084D.20002-/MT0OVThwyLZJqsBc5GL+g@public.gmane.org>
2014-11-20 0:13 ` [PATCH v2] selftest: size: Add size test for Linux kernel Tim Bird
[not found] ` <546D321F.2080405-/MT0OVThwyLZJqsBc5GL+g@public.gmane.org>
2014-11-20 21:58 ` Shuah Khan
[not found] ` <546E640F.1090006-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
2014-11-24 18:08 ` Tim Bird
2014-11-24 18:20 ` [PATCH v3] " Tim Bird
[not found] ` <547376D3.7070709-/MT0OVThwyLZJqsBc5GL+g@public.gmane.org>
2014-11-25 20:39 ` Shuah Khan
[not found] ` <5474E8F6.8010307-JPH+aEBZ4P+UEJcrhfAQsw@public.gmane.org>
2014-11-25 23:33 ` Tim Bird
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=546D084D.20002@sonymobile.com \
--to=tim.bird@sonymobile.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-embedded@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=shuahkh@osg.samsung.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).